well i just responded to the other one... man you should just start a single thread for this stuff, it would be way way easier.
anyway... engine ice is good stuff.
i would bet there is a drain on the bottom of it too. i would never blow it with air, but i would bet you probably did it already. water would be the only way to go in my book.
you could run water through the top and just keep the "middle" open and let it flush through unlike the other thread to let it fill. it would already be filled up a little as it flushes.
steve
2019 Maverick X3 XDS Turbo R
2003 TRX 400EX
2016 HONDA RANCHER